Tension spring clip comprising symmetrical tension springs

ABSTRACT

A draw spring clamp has loopshaped draw springs with an attachment leg to contact a current bus and with a spring leg and clamping leg, whereby the latter is interrupted by a clamp window in order to form the clamp leg. By means of an actuation element into which a tool blade may be inserted, the spring leg of the draw springs may be loaded with tension in order to open the clamp window. This actuation element is located between the two spring legs of the draw spring that oppose each other. In order to enable time-saving actuation, the actuation element in its loaded position also rests against the two spring legs. Thus, the actuation element possesses rest positions on its opposing exteriors whose separation increases along a first direction of travel of the actuation element and decreases along the second, direction.

TECHNICAL FIELD

The invention relates to a draw spring clamps with two draw springspositioned in mirror-image layout within a housing.

BACKGROUND INFORMATION

The invention relates to a draw spring clamps with two draw springspositioned in mirror-image layout within a housing. Each of these drawsprings possesses an attachment leg resting on a current bus as well asa spring leg that is of one piece with it and that is bent together withthe attachment leg into a loop. The attachment leg of the pertinent drawsprings extends with its end and with the current bus through the clampwindow. The two spring legs of the draw springs are positioned facingeach other, and are loadable with tension by means of an actuationelement that is positioned within a housing of the draw spring clampinto which a tool blade may be inserted for the purpose of providingspring tension along the direction toward the attachment leg when theclamp window is opened. The above-mentioned actuation element is locatedbetween the two opposing spring legs, and also rests in its tensioningposition against both spring legs, and also possesses a correspondingrest position on opposing exterior sides for the spring legs of bothdraw springs.

This type of draw spring clamp is known generally. According to suchdevices, the actuation element is formed as an oval, rotatable body thatcorrespondingly possesses a maximum diameter and a minimum diameter. Inthe rotational position of the actuation element at which the maximumdiameter is located within the symmetry plane of the draw springs, theirspring legs are not tensioned. In the position rotated by 90? in whichthe maximum diameter of the actuation element is perpendicular to thesymmetry plane of the draw springs, their spring legs are tensioned withforce and correspondingly are deflected toward each attachment leg ofthe draw spring, whereby the clamp windows of both draw springs areopen. The actuation element includes an insertion slot for a screwdriverblade so that it may be rotated. This involves not only the rotation ofthe actuation element the rotational position to load the spring legs ofthe draw springs, from which rotational position the actuation elementmust be reset by means of a screwdriver blade.

Another type of draw spring is known wherein the actuation element isformed as a slider that may move along a guide formed by the clamphousing. This actuation element assumes an initial position in which itis located between the two opposing spring legs of the draw springs.From this initial position, it may be displaced to the one side towardthe first draw spring, and to the other side toward the second drawspring, in order to tension the spring leg of the pertinent draw springand to open the clamp window of the draw spring. Thus, the two clampwindows of the draw springs may be opened only sequentially.

A draw spring clamp of yet another type is known whereby two pivotableactuation pressers are present to tension the spring legs of the twodraw springs that include pressure jaws into which engagement may occurusing a screwdriver blade. These actuation pressers are formed as leverswith unequal arms, whereby the presser jaw is located on the one leverarm to tension the spring leg of the pertinent draw spring. With thistype of device, the clamp positions may also only be servicedsequentially, whereby here even the tool between the actuation pressersmust be reset.

Draw spring, clamps of the above-mentioned type are particularly used asplug-in modules. Each of the two draw springs of the clamp herebyreceives one of the two connection cables of a cabled module or thelike.

SUMMARY

It is one goal of the invention to provide a draw spring clamp by meansof which switching of such cabled modules is made especially simpler andless time-consuming, and in which reset of the actuation element isachieved automatically when the actuation tool is removed.

Such a goal is achieved by a draw spring clamp of the above-mentionedtype in that the actuation element is formed as an elastic or partiallyelastic spreading body that may be stretched toward the spring legs ofthe draw spring by insertion of the tool blade using its exterior sides.

It is essential to the invention that the actuation element be formed asa spreading body that may be stretched bay the insertion of aconventional, wedge-shaped screwdriver blade, which resultantly appliesforce caused by this spreading to the two adjacent spring legs of thetwo draw spring clamps. Without multiple rotational or slidedisplacements, the two clamp positions in the area of the clamp windowof the two draw springs are opened and closed simultaneously, by meansof which a cabled module may be clamped by, or removed from, the drawspring clamp as a plug-in module with both connector cables also clampedby or removed from, the two draw springs. The elastic actuation elementis reset automatically upon removal of the tool blade, thus releasingthe spring legs of the draw springs again. This achieves a positiveclamping of the cabled module since release of the draw springs with theactuation tool removed is not possible.

Thus, a draw spring clamp in accordance with the present invention hasloop-shaped draw springs with an attachment leg to contact a current busand with a spring leg and clamping leg, whereby the latter isinterrupted by a clamp window in order to form the clamp leg. By meansof an actuation element into which a tool blade may be inserted, thespring leg of the draw springs may be loaded with tension in order toopen the clamp window. This actuation element is located between the twospring legs of the draw spring that oppose each other. In order toenable time-saving actuation, the actuation element in its loadedposition also rests against the two spring legs. Thus, the actuationelement possesses rest positions on its opposing exteriors whoseseparation increases along a first direction of travel of the actuationelement and decreases along the second direction.

It is important to note that the present invention is not intended to belimited to a system or method which must satisfy one or more of anystated objects or features of the invention. It is also important tonote that the present invention is not limited to the preferred,exemplary, or primary embodiment(s) described herein. Modifications andsubstitutions by one of ordinary skill in the art are considered to bewithin the scope of the present invention, which is not to be limitedexcept by the following claims.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bebetter understood by reading the following detailed description, takentogether with the drawings wherein:

FIG. 1 is a cutaway side view of a draw spring clamp according to thepresent invention; and

FIG. 2 is a perspective view of the draw spring clamp per FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

One may recognize in detail in the illustrations a clamp housing 1 onwhose underside a plug element 2 is formed in order to be able to usethe draw spring clamp as a plug-in module. As FIG. 1 reveals, two drawsprings 3 that are positioned in mirror-image configuration. Each ofthese two draw springs 3 includes an attachment leg 4 that rests on acurrent bus 5. Made of one piece with the attachment leg 4 is a springleg 6 that is bent into a loop along with the attachment leg 4. Thus,bent back toward the attachment leg 4, the spring leg 6 possesses aclamp leg 7 that is penetrated by a clamp window 6. The attachment leg 4with its end 9 and the current bus 5 extend through this clamp window 8.

The two draw springs 3 provide contact for a module 10, such as anelectronic component or the like, that has a cable or central region,and from which two connector cables or wires 11 correspondingly extend.Each of these wires 11 is clamped to one of the clamp positions in thearea of the clamp window 8 of the draw springs 3 in that they aretensioned through the pertinent clamp window 8 by means of the springleg 6 of the draw spring 3 against the side of the current bus 5 facingaway from the attachment leg 4. The mirror-image spring legs 6 of thedraw springs 3 must be tensioned with force for insertion into the clampwindows 8 and for release from the clamp positions, whereby the springlegs 6 feed in the direction toward the attachment legs 4, andcorrespondingly the clamp windows a are opened within the clamp legs 7of the draw springs 3.

This actuation of the draw springs 3, namely the tensioning of theirmirror-image spring legs 6, is performed simultaneously. An actuationelement 12 serves for this that is positioned between the two springlegs 6 of the draw springs 3. The actuation element 12 formedlongitudinally and symmetrically in the direction of the symmetry planeof the two draw springs 3 includes an insertion slot 13 into which atool blade 14 flattened on both sides, such as a screwdriver, may beinserted. Since the actuation element 12 consists of an elasticmaterial, and is correspondingly stretchable, the actuation element 12may be so stretched by the tool blade 14 that force is exerted againstthe spring legs 6 of the draw springs 3.

In order to expand the actuation element 12, the longitudinal walls 19of the actuation element 12 that define the insertion slot 13 and formthe exterior side are elastically expandable. For one thing, the wedgeforce exerted by the tool blade may be used to expand the actuationelement 12. If this is insufficient, such expansion of the actuationelement 13 may be performed by rotation of the tool blade 14 positionedwithin the insertion slot 12 because the tool blade 14 rests crosswiserelative to the insertion slot 13. Upon removal of the tool lade 14, theelastic actuation element automatically resets, releasing the spring leg6.

The longitudinal exterior sides 17 of the actuation element 12 may benot merely rest points, but rather may form rest surfaces for the springlegs 6 of the draw springs 3, and may be matched to the exterior shapeof the draw springs 6 in that they (as shown for the embodiment example)possess the progression of a flat recess that transforms to a roundedlower edge 18. Thus, sharp edges wedging with the exterior sides of thespring legs 6 of the draw springs 3 are avoided.

FIG. 2 shows clearly that the tool blade 14 may be used from one of thebroad, parallel sides of the clamp housing 1, and may even extendthrough the clamp housing 1. Thus, at least the pertinent wall 15 of theclamp housing 1 possesses a hole 16 through which the tool blade 11 maybe inserted into the actuation element 12 behind it. The cabled module10 is inserted with its connector cables 11 away from the open upperside of the clamp housing 1 facing away from the plug element. Thus,manipulation is practical because the inserted tool blade 14 and theconnector cables 11 of the module 10 to be connected or disconnected donot interfere with each other.

As mentioned above, the present invention is not intended to be limitedto a system or method which must satisfy one or more of any stated orimplied object or feature of the invention and should not be limited tothe preferred, exemplary, or primary embodiment(s) described herein. Theforegoing description of a preferred embodiment of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed. Obvious modifications or variation are possible in light ofthe above teachings. The embodiment was chosen and described to providethe best illustration of the principles of the invention and itspractical application to thereby enable one of ordinary skill in the artto utilize the invention in various embodiments and with variousmodifications as is suited to the particular use contemplated. All suchmodifications and variations are within the scope of the invention asdetermined by the claims when interpreted in accordance with the breadthto which they are fairly, legally and equitably entitled.

1. A draw spring clamp with two draw springs positioned within a housingin mirror-image configuration, each of which possesses an attachment legresting on a current bus and a spring leg with a clamp window that is ofone piece with it and that is bent together with the attachment leg intoa loop, through which clamp window an end of the attachment leg and thecurrent bus extend, whereby the two spring legs are positioned inmirror-image configuration and the spring legs may be tensioned by meansof an actuation element that is positioned within a housing of the drawspring clamp, into which a tool blade may be inserted for the purpose ofproviding spring tension along the direction toward the attachment legwhen the clamp window is opened, whereby the actuation element islocated between the two mirror-image spring legs of the draw springs andrests evenly on both spring legs in the tensioned position, andpossesses rest surfaces for the spring legs of both draw springscorrespondingly on opposite exterior sides, of both draw springscorrespondingly on opposite exterior sides, characterized in that theactuation element is formed as an elastic or partially-elastic spreadingbody that may be stretched toward and against both the two spring legsof the two draw spring by insertion of the tool blade using its exteriorsides.
 2. A draw spring clamp as in claim 1, wherein the longitudinalwalls of the actuation element defining the insertion slot areelastically expandable.
 3. A draw spring clamp as in claim 1, whereinthe actuation element is formed and positioned to be mirror-imagesymmetrical to the symmetry plane of the draw springs (3).
 4. A drawspring clamp as in claim 3, wherein the actuation element possesses aninsertion slot longitudinal in the symmetry plane for a correspondingtool blade.
 5. A draw spring clamp as in claim 4, wherein the clamphousing possesses a pass-through opening for the tool blade in at leastone of two walls of the actuation element that are parallel to the holeplane off the insertion slot aligned in the direction crosswise to thishole plane with the insertion slot.
 6. A draw spring clamp as in claim1, wherein the actuation element is formed longitudinally in thedirection toward the symmetry plane of the draw springs.